Denys Finch-Hatton, who wrote Of Cakes and Kings: Royal Weddings from Ethelred to Peter Philips, said: “In the Massive Wedding Decree of 1257 Henry III said all future heirs to the throne must spend at least 38 gold sovereigns, or its index linked equivalent, on a dress, a cake and a band. They didn’t have police then. Or overtime.”

He added: “Prince Charles actually wanted to get married under a tree – or maybe it was to a tree – but the Queen told him that if he did he could never be king.

“She got out the original copy of Henry III’s decree and explained to him his constitutional duty to have 27 wedding cakes and the Red Arrows.”

Finch-Hatton also stressed that huge weddings were necessary to impress greasy foreigners whose mounted soldiers were nowhere near as shiny as ours.

A French embassy spokesman said: “We never cease to be impressed by Britain. Particularly its ability to piss money up a rope on shit like this. Have you thought about maybe spending the cash on a train that can do more than 20 fucking miles an hour?”

Meanwhile experts warned that in addition to the constitutional and foreigner-impressing obligations, it was very important that people had something to watch on television on a Saturday afternoon in the middle of July.

Julian Cook, from Reading University said: “If there wasn’t a Royal Wedding then the broadcasters probably wouldn’t bother putting on any other programmes. It would just be a blank screen.

“It’s not like BBC2 is suddenly going to show Ben Hur on a Saturday afternoon because there isn’t a Royal Wedding. Actually, you know what, they should totally show Ben Hur. I haven’t seen that for ages.

“If they do, I’ll invite all my friends and neighbours over and we’ll have a few drinks, I’ll make a Ben Hur cake and put up some Ben Hur bunting. Ben Hur is a really, really good film. And it has excellent costumes.”

But Helen Archer, a patriot thank you very much from Grantham, said: “We have to have all the pomp and ceremony because that’s what being British is all about.

“It’s not about anything else. There is nothing else that is British. It’s just that.”

Cook added: “Or they could show The Godfather, that’s really good too.